Table 1-17 Classification of relays according to the principle of action name  Weigh Principle of action The main purpose Voltage relay Act when the terminal voltage in the circuit reaches the specified value For motor loss, overvoltage and undervoltage, as well as braking and reversing control Current relay Act when the current in the circuit reaches the specified value For overload and short circuit protection of motors, DC motor field control System or loss of field protection Intermediate relay Same voltage relay Used to propagate and amplify signals, or to pass signals to several controls Component Time Relay Using electromagnetic damping, air damping, electronic circuits Wait for the signal to move to the contact for a certain time interval For winding rotor motor switching on time basis Acceleration relay of resistance, cage asynchronous motor Y- △ start, Energy consumption braking and control of various production process procedures, etc. Self-locking relay The mechanical self-locking relay is self-locking by mechanical lock; Magnetic self-locking relay realizes on-off by current pulse Memory element for use in automatic control systems all in one energy;all in one battery,home battery,home energy storage,household power storage,home solar power,all in one system Shenzhen Enershare Technology Co.,Ltd , https://www.enersharepower.com
  There are many types and uses of electromagnetic relays. It is classified according to the principle of action as shown in Table 1-17 .